Monoester compounds of cycloalkane dicarboxylic acids are compounds that are useful as production intermediates for liquid-crystal materials, electron transport materials, and the like (for example, refer to PTL 1). These monoester compounds are normally synthesized through reaction of a dicarboxylic acid chloride and a hydroxy compound.
One known method of producing a dicarboxylic acid chloride is a method (acid halide method) in which a chlorinating agent such as thionyl chloride is caused to act on a dicarboxylic acid compound in the presence of a reaction catalyst (herein, also referred to as an “activator”) such as N,N-dimethylformamide, triethylamine, or a tetraalkylammonium salt.
For example, PTL 2 describes a method of producing 5-amino-2,4,6-triiodoisophthalic acid dichloride by reacting thionyl chloride with 5-amino-2,4,6-triiodoisophthalic acid in the presence of a tetraalkylammonium salt.
Moreover, PTL 3 describes a method of producing an ester group-containing tetracarboxylic dianhydride having a specific structure by the acid halide method. Furthermore, PTL 3 explains that when reacting thionyl chloride with a dicarboxylic acid, N,N-dimethylformamide or pyridine may be added to the reaction system as a catalyst.
Also, NPL 1 describes a method of producing a dichloride of a dicarboxylic acid by reacting thionyl chloride with a dicarboxylic acid having a specific structure in the presence of benzyltriethylammonium chloride.